tree 620aca488e568d757f41486fe28c0f44297d61bf
parent b2edfb89ccb534ff882954328c0d65d6721bd688
author Jeff Genovy <29107334+jefgen@users.noreply.github.com> 1600892476 -0700
committer Jeff Genovy <29107334+jefgen@users.noreply.github.com> 1601413059 -0700

ICU-13845 Windows timezone detection: When DST is off, map to an Etc/GMT+-hh zone.

The Windows 'Date and Time' Control Panel has a setting for "Automatically
adjust clock for DST". When this setting is manually unchecked, the DST
setting is considered OFF, and the clock does not adjust for DST.

This change detects when the setting is OFF and uses the non-DST offset
to map to an Etc/GMT+-hh zone.

- Also refactor uprv_detectWindowsTimeZone

Co-authored-by: Jungshik Shin <jshin@chromium.org>